It must distil thousands of years of history into just over an hour, reflect a nation unto itself, promote Britain to the world, satisfy the demands of politicians and organisers, entertain 1bn viewers and bring the curtain up on the planet's biggest sporting event. So no pressure.

Film director Danny Boyle, the creative director of Friday night's £27m London 2012 opening ceremony, has already admitted that it will be an impossible task to satisfy everyone.

Instead, he has produced what has been described by overall ceremonies creative chief Stephen Daldry as a "singular vision", with music by electronic duo Underworld and other top British acts and with a denouement they are confident will stay secret despite the best efforts of the media.

The identity of the person who will light the Olympic cauldron is also a closely guarded secret, but bookmaker William Hill suspended betting on Thursday on Roger Bannister, the first man to run a four-minute mile, after a run of big bets.

Earlier, Team GB chef de mission Andy Hunt, who has some input into the decision, said a number of Britain's "truly great Olympians" would be involved in the "final sequence" of the ceremony, but would not reveal the identity of the cauldron lighter. British Olympic Association chairman Lord Moynihan was keen for Sir Steve Redgrave, winner of five Olympic gold medals for rowing, to light the cauldron, but Hunt's comments suggest he will be part of the final countdown rather than the ultimate bearer of the flame.

Boyle this week paid tribute to the 10,000 volunteers who have rehearsed for months, first in the old Ford plant in Dagenham, Essex, and then in the stadium, often in atrocious weather, to bring his script to life.

"This is a show that has been built out of our volunteers – 10,000 people who've turned up in rain and terrible conditions. This show is theirs, this country is theirs, they really are the best of us," he said.

A troupe of nurses are among those appearing, even though culture secretary Jeremy Hunt is believed to have questioned their inclusion at a time when government NHS reforms have provoked controversy. Footballer David Beckham will also play a role, he has confirmed.

"The ceremony is an attempt to capture a picture of ourselves as a nation, where we have come from and where we want to be," the director of Trainspotting and the Oscar-winning Slumdog Millionaire has said.

The show, titled Isles of Wonder after a speech by Caliban in Shakespeare's The Tempest, begins with a pastoral vision of a "green and pleasant land" complete with real sheep, pigs and goats, before transforming into a more urban landscape to reflect the "dark satanic mills" of William Blake's Jerusalem.

It will begin at 9pm with the ringing of the largest harmonically tuned bell in the world, which hangs at one end of the stadium.

Preceding the main event, beginning at the symbolic time of 20.12, will be a warm-up show, chiefly designed to get the crowd in the mood.

The prime minister, David Cameron, said on Thursday he had no fears about Boyle's ability to deliver.

"I've had some presentation meetings with Danny Boyle and Stephen Daldry and others and spoken to people lucky enough to go to the rehearsals. I've always had that tingling feeling on my spine and the hairs standing on the back of my neck with the treatment they're giving it," he said.Whereas Beijing's opening ceremony was remembered for its jaw-dropping scale, Daldry said Boyle would employ creativity and humour.

Cameron acknowledged the size of the task, but said Boyle was up to it.

"We have to celebrate all that is great about the past but also all the potential Britain has in the future. There are so many things to celebrate about our country that packing all that in must be a pretty tough task."

Asked whether the message of the opening ceremony would be Beefeaters or Blur, he said: "Both."

The three-and-a-half-hour ceremony, which has had to be tightened up by 40 minutes to avoid overrunning, comprises the hour-long cultural showcase, the parade of athletes and officials from 204 nations and the protocol of flags, anthems and speeches, before the lighting of the cauldron and the obligatory fireworks.

The International Olympic Committee has issued a no dawdling edict, asking for athletes to maintain a steady pace around the track in order to keep the show on time. Some of Team GB's biggest names will be missing because they have not yet checked into the athletes' village or because they are competing within 48 hours of the ceremony.

Hunt said 260 of Team GB's 542 athletes would take part in the parade, led by flag bearer Sir Chris Hoy. Only 40 British officials will parade because numbers have been limited for the first time to speed proceedings along.

About 120,000 people who attended dress rehearsals on Monday and Wednesday have been asked to "save the surprise" and not reveal what they had seen. The campaign has been largely successful, although organisers had to step in to have a handful of videos removed from YouTube.